public class Example4_5 {
    public static void main(String args[]) {
	Rect ractangle = new Rect();
	ractangle.width=109.87;
	ractangle.height=25.18;
	double area = ractangle.getArea();
	System.out.println("矩形的面积:"+area);
	Lader lader = new Lader();
	lader.above = 10.798;
	lader.bottom = 156.65;
	lader.height = 18.12;
	area = lader.getArea();
	System.out.println("梯形的面积:"+area);
	}
}
